playing a bout around with nvdisasm, there seems to be some
complications with certain sched opcodes. I think we should figure out
if this is simply nvdisasm crashing or if this is a real hardware
thing.
On Tue, Jul 17, 2018 at 9:26 PM, Rhys Perry <pendingchao...@gmail.com> wrote:
> After some testing and looking at traces of the blob or nvcc output,
> it seems the only system value CS2R is useful for is SV_CLOCK.
>
> On Tue, Jul 17, 2018 at 1:09 PM, Karol Herbst <kher...@redhat.com> wrote:
>> that seems like a good enough improvement. I think looking onto other
>> sysvals would be worthwhile as SV_CLOCK isn't used that often. The
>> invocation ID and related ones would be interesting to look into as
>> they are much more common.
>>
>> On Tue, Jul 17, 2018 at 1:59 PM, Rhys Perry <pendingchao...@gmail.com> wrote:
>>> I'm getting ~28 cycles for the S2R and ~6 cycles (unsurprisingly) for the
>>> CS2R.
>>>
>>> nvcc with SM30 seems to use the same instruction as the nvc0 emission code.
>>>
>>> The SV_LANE* system values don't work with CS2R and I haven't looked
>>> too deeply into the others.
>>>
>>> On Tue, Jul 17, 2018 at 12:13 PM, Karol Herbst <kher...@redhat.com> wrote:
>>>> interesting, do you have some numbers on that? Wondering if we could
>>>> switch more sysvals over to it and what about older gens?
>>>>
>>>> On Tue, Jul 17, 2018 at 12:46 PM, Rhys Perry <pendingchao...@gmail.com>
>>>> wrote:
>>>>> This instruction seems to be faster than S2R and requires no barrier,
>>>>> though the range of special registers it can read from is limited.
>>>>>
>>>>> Signed-off-by: Rhys Perry <pendingchao...@gmail.com>
>>>>> ---
>>>>> src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp | 14
>>>>> +++++++++++++-
>>>>> .../drivers/nouveau/codegen/nv50_ir_target_gm107.cpp | 4 +++-
>>>>> 2 files changed, 16 insertions(+), 2 deletions(-)
>>>>>
>>>>> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp
>>>>> b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp
>>>>> index 694d1b10a3..c306a4680b 100644
>>>>> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp
>>>>> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp
>>>>> @@ -124,6 +124,7 @@ private:
>>>>>
>>>>> void emitMOV();
>>>>> void emitS2R();
>>>>> + void emitCS2R();
>>>>> void emitF2F();
>>>>> void emitF2I();
>>>>> void emitI2F();
>>>>> @@ -749,6 +750,14 @@ CodeEmitterGM107::emitS2R()
>>>>> emitGPR (0x00, insn->def(0));
>>>>> }
>>>>>
>>>>> +void
>>>>> +CodeEmitterGM107::emitCS2R()
>>>>> +{
>>>>> + emitInsn(0x50c80000);
>>>>> + emitSYS (0x14, insn->src(0));
>>>>> + emitGPR (0x00, insn->def(0));
>>>>> +}
>>>>> +
>>>>> void
>>>>> CodeEmitterGM107::emitF2F()
>>>>> {
>>>>> @@ -3192,7 +3201,10 @@ CodeEmitterGM107::emitInstruction(Instruction *i)
>>>>> emitMOV();
>>>>> break;
>>>>> case OP_RDSV:
>>>>> - emitS2R();
>>>>> + if (insn->getSrc(0)->reg.data.id == SV_CLOCK)
>>>>> + emitCS2R();
>>>>> + else
>>>>> + emitS2R();
>>>>> break;
>>>>> case OP_ABS:
>>>>> case OP_NEG:
>>>>> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_target_gm107.cpp
>>>>> b/src/gallium/drivers/nouveau/codegen/nv50_ir_target_gm107.cpp
>>>>> index 04cbd402a1..009470fb93 100644
>>>>> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_target_gm107.cpp
>>>>> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_target_gm107.cpp
>>>>> @@ -153,9 +153,10 @@ TargetGM107::isBarrierRequired(const Instruction
>>>>> *insn) const
>>>>> case OP_AFETCH:
>>>>> case OP_PFETCH:
>>>>> case OP_PIXLD:
>>>>> - case OP_RDSV:
>>>>> case OP_SHFL:
>>>>> return true;
>>>>> + case OP_RDSV:
>>>>> + return insn->getSrc(0)->reg.data.id != SV_CLOCK;
>>>>> default:
>>>>> break;
>>>>> }
>>>>> @@ -229,6 +230,7 @@ TargetGM107::getLatency(const Instruction *insn) const
>>>>> case OP_SUB:
>>>>> case OP_VOTE:
>>>>> case OP_XOR:
>>>>> + case OP_RDSV:
>>>>> if (insn->dType != TYPE_F64)
>>>>> return 6;
>>>>> break;
>>>>> --
>>>>> 2.14.4
>>>>>
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